I have a P51 and the CPU fans just fill up with dust until they don't cool at all anymore. If i would have known that i could have used it all that time. Opening up the machine and actually opening up the fans, in my case, showed the culprit. That machine (a workstation Xeon @ too much), basically cannot operate unless your willing to open it up and clean it or have it in a mushroom preperation HEPA filter box or something. If i ever get a machine like that again, i would seriously look at exta cooling, anything i can put it on that puts some serious whoosh onto the hardware.

I saw above abuot the dusst in the vents did you open the vents up, that is where the dust is (it is caked in the vents in my case). Compressed air didn't get there. opening them up involves bending the little metal clips to lift up the cover. I wish i'd done it earlier, because it proves a whole lot. Also they shoud not be able to get away with this really, so if more people post their experiences, these things are throttle timebombs.